package cn.com.kh;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import javax.crypto.spec.IvParameterSpec;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.commons.codec.binary.Base64;

public class DESEncrypt {
    private static final Log log = LogFactory.getLog(DESEncrypt.class);

    public static String Encrypt(String key, String value) throws Exception {

        log.debug("加密密匙:" + key + "	加密数据:" + value);

        String a = toHexString(encrypt(value, key));
        log.debug("加密后的数据:" + a);

        a = Base64.encodeBase64(encrypt(value, key)).toString();

        return a;

    }

    // 解密数据
    public static String decrypt(String message, String key) throws Exception {

        byte[] bytesrc = convertHexString(message);
        Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
        DESKeySpec desKeySpec = new DESKeySpec(key.getBytes("UTF-8"));
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
        SecretKey secretKey = keyFactory.generateSecret(desKeySpec);
        IvParameterSpec iv = new IvParameterSpec(key.getBytes("UTF-8"));

        cipher.init(Cipher.DECRYPT_MODE, secretKey);

        byte[] retByte = cipher.doFinal(bytesrc);
        return new String(retByte);
    }

    public static byte[] encrypt(String message, String key) throws Exception {
        Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");

        DESKeySpec desKeySpec = new DESKeySpec(key.getBytes("UTF-8"));

        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
        SecretKey secretKey = keyFactory.generateSecret(desKeySpec);
        IvParameterSpec iv = new IvParameterSpec(key.getBytes("UTF-8"));
        cipher.init(Cipher.ENCRYPT_MODE, secretKey);

        return cipher.doFinal(message.getBytes("UTF-8"));
    }

    public static byte[] convertHexString(String ss) {
        byte digest[] = new byte[ss.length() / 2];
        for (int i = 0; i < digest.length; i++) {
            String byteString = ss.substring(2 * i, 2 * i + 2);
            int byteValue = Integer.parseInt(byteString, 16);
            digest[i] = (byte) byteValue;
        }

        return digest;
    }

    public static String toHexString(byte b[]) {
        StringBuffer hexString = new StringBuffer();
        for (int i = 0; i < b.length; i++) {
            String plainText = Integer.toHexString(0xff & b[i]);
            if (plainText.length() < 2)
                plainText = "0" + plainText;
            hexString.append(plainText);
        }

        return hexString.toString();
    }

}